Among ionic, covalent, hydrogen, and metallic bonds, which is generally the weakest?

Among ionic, covalent, hydrogen, and metallic bonds, which is generally the weakest?

• A. Ionic bond
• B. Covalent bond
• C. Hydrogen bond
• D. Metallic bond

Answer: (C)

Hydrogen bonds are the weakest among these bond types because they are intermolecular attractions, not the actual bonds that hold atoms together in a molecule. In a hydrogen bond, a hydrogen atom covalently attached to a highly electronegative atom (like oxygen, nitrogen, or fluorine) is attracted to a lone pair on another electronegative atom nearby. This electrostatic interaction is relatively weak compared with the strong electron sharing in covalent bonds, and with the full coulombic attraction between oppositely charged ions in ionic bonds. Metallic bonds rely on a delocalized electron cloud that binds many atoms together, which tends to be quite strong as well. Typical hydrogen-bond energies are only a fraction of covalent or ionic bond energies, so they’re generally the weakest.

Hydrogen bonds are the weakest among these bond types because they are intermolecular attractions, not the actual bonds that hold atoms together in a molecule. In a hydrogen bond, a hydrogen atom covalently attached to a highly electronegative atom (like oxygen, nitrogen, or fluorine) is attracted to a lone pair on another electronegative atom nearby. This electrostatic interaction is relatively weak compared with the strong electron sharing in covalent bonds, and with the full coulombic attraction between oppositely charged ions in ionic bonds. Metallic bonds rely on a delocalized electron cloud that binds many atoms together, which tends to be quite strong as well. Typical hydrogen-bond energies are only a fraction of covalent or ionic bond energies, so they’re generally the weakest.